In this project, the investigator is proposing to make a long term investigation of the host blood feeding pattern of mosquitoes from various habitats in Mississippi. Studies on blood feeding patterns of mosquitoes, such as these, will aid in assessing the interactions between mosquitoes, host and the environment. This type of information will increase our knowledge of the role of various mosquito species and potential hosts in disease cycles in Mississippi, and eventually in determining effective mosquito control strategies. The occurrence of St. Louis Encephalitis in certain area of the state and the documentation of Dengue Fever in the Gult Coast of Mississippi indicate that the pathogens of these diseases are endemic in certain parts of the state and thus the need to investigate the mosquito-host feeding relationship. Sampling stations will be established in urban, rural, farmland and recreational areas in the following regions of the state: Delta area, Central region and the Gulf Coast. Blood engorged mosquitoes will be collected from April to September, each year, using miniature battery operated CDC light traps and back pack or hand battery operated aspirators. In the laboratory, engorged mosquitoes will be counted and identified to species. Identification of host blood meal will be made by using the Capillary Precipitant Test.